配置Kafka Connect分布式连接器日志（connectDistributed.out）

Question

Currently two types of Kafka Connect log are being collected.

• connect-rest.log.2018-07-01-21 , connect-rest.log.2018-07-01-22 ...
• connectDistributed.out

The thing is that I don't know how to configure connectDistributed.out file in Kafka Connect. Following is the sample output of the file:

[2018-07-11 08:42:40,798] INFO WorkerSinkTask{id=elasticsearch-sink- 
connector-0} Committing offsets asynchronously using sequence number 
216: {test-1=OffsetAndMetadata{offset=476028, metadata=‘’}, 
test-0=OffsetAndMetadata{offset=478923, metadata=‘’}, 
test-2=OffsetAndMetadata{offset=477944, metadata=‘’}} 
(org.apache.kafka.connect.runtime.WorkerSinkTask:325)
[2018-07-11 08:43:40,798] INFO WorkerSinkTask{id=elasticsearch-sink-connector0} 
Committing offsets asynchronously using sequence number 217: 
{test-1=OffsetAndMetadata{offset=476404, metadata=‘’}, 
test-0=OffsetAndMetadata{offset=479241, metadata=‘’}, 
test-2=OffsetAndMetadata{offset=478316, metadata=‘’}} 
(org.apache.kafka.connect.runtime.WorkerSinkTask:325)

Not having configured any logging option, the file size is getting bigger as time goes by. Today, it reached 20GB and I had to manually empty the file. So my question is how do I configure this connectDistributed.out ? I'm configuring log options for other components such as the kafka broker log.

---

Following is some of the Kafka Connect-related log configurations under confluent-4.1.0/etc/kafka that I'm using.

log4j.properties

log4j.appender.requestAppender.File=${kafka.logs.dir}/kafka-request.log
log4j.appender.requestAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.requestAppender.layout.ConversionPattern=[%d] %p %m (%c)%n

log4j.appender.cleanerAppender=org.apache.log4j.DailyRollingFileAppender
log4j.appender.cleanerAppender.DatePattern='.'yyyy-MM-dd-HH
log4j.appender.cleanerAppender.File=${kafka.logs.dir}/log-cleaner.log
log4j.appender.cleanerAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.cleanerAppender.layout.ConversionPattern=[%d] %p %m (%c)%n

log4j.appender.controllerAppender=org.apache.log4j.DailyRollingFileAppender
log4j.appender.controllerAppender.DatePattern='.'yyyy-MM-dd-HH
log4j.appender.controllerAppender.File=${kafka.logs.dir}/controller.log
log4j.appender.controllerAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.controllerAppender.layout.ConversionPattern=[%d] %p %m (%c)%n

log4j.appender.authorizerAppender=org.apache.log4j.DailyRollingFileAppender
log4j.appender.authorizerAppender.DatePattern='.'yyyy-MM-dd-HH
log4j.appender.authorizerAppender.File=${kafka.logs.dir}/kafka-authorizer.log
log4j.appender.authorizerAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.authorizerAppender.layout.ConversionPattern=[%d] %p %m (%c)%n

# Change the two lines below to adjust ZK client logging
log4j.logger.org.I0Itec.zkclient.ZkClient=INFO
log4j.logger.org.apache.zookeeper=INFO

# Change the two lines below to adjust the general broker logging level (output to server.log and stdout)
log4j.logger.kafka=INFO
log4j.logger.org.apache.kafka=INFO

# Change to DEBUG or TRACE to enable request logging
log4j.logger.kafka.request.logger=WARN, requestAppender
log4j.additivity.kafka.request.logger=false

# Uncomment the lines below and change log4j.logger.kafka.network.RequestChannel$ to TRACE for additional output
# related to the handling of requests
#log4j.logger.kafka.network.Processor=TRACE, requestAppender
#log4j.logger.kafka.server.KafkaApis=TRACE, requestAppender
#log4j.additivity.kafka.server.KafkaApis=false
log4j.logger.kafka.network.RequestChannel$=WARN, requestAppender
log4j.additivity.kafka.network.RequestChannel$=false

log4j.logger.kafka.controller=TRACE, controllerAppender
log4j.additivity.kafka.controller=false

log4j.logger.kafka.log.LogCleaner=INFO, cleanerAppender
log4j.additivity.kafka.log.LogCleaner=false

log4j.logger.state.change.logger=TRACE, stateChangeAppender
log4j.additivity.state.change.logger=false

# Access denials are logged at INFO level, change to DEBUG to also log allowed accesses
log4j.logger.kafka.authorizer.logger=INFO, authorizerAppender
log4j.additivity.kafka.authorizer.logger=false

connect-log4j.properties

log4j.rootLogger=INFO, stdout

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=[%d] %p %m (%c:%L)%n

log4j.logger.org.apache.zookeeper=ERROR
log4j.logger.org.I0Itec.zkclient=ERROR
log4j.logger.org.reflections=ERROR


log4j.appender.kafkaConnectRestAppender=org.apache.log4j.DailyRollingFileAppender
log4j.appender.kafkaConnectRestAppender.DatePattern='.'yyyy-MM-dd-HH
log4j.appender.kafkaConnectRestAppender.File=/home/ec2-user/logs/connect-rest.log
log4j.appender.kafkaConnectRestAppender.layout=org.apache.log4j.PatternLayout
log4j.appender.kafkaConnectRestAppender.layout.ConversionPattern=[%d] %p %m (%c)%n

log4j.logger.org.apache.kafka.connect.runtime.rest=INFO, kafkaConnectRestAppender
log4j.additivity.org.apache.kafka.connect.runtime.rest=false

Answer 1

The connectDistributed.out file only exists if you use daemon mode, eg

connect-distributed -daemon connect-distributed.properties

Reason : From kafka-run-class script, CONSOLE_OUTPUT_FILE is set to connectDistributed.out

# Launch mode
if [ "x$DAEMON_MODE" = "xtrue" ]; then
    nohup $JAVA $KAFKA_HEAP_OPTS $KAFKA_JVM_PERFORMANCE_OPTS $KAFKA_GC_LOG_OPTS $KAFKA_JMX_OPTS $KAFKA_LOG4J_OPTS -cp $CLASSPATH $KAFKA_OPTS "$@" > "$CONSOLE_OUTPUT_FILE" 2>&1 < /dev/null &
else... 

---

Option 1: Load a custom log4j property file

You can update the KAFKA_LOG4J_OPTS environment variable to point at any log4j property file that you want to before starting connect (see example below)

$ export KAFKA_LOG4J_OPTS="-Dlog4j.configuration=file://path/to/connect-log4j-new.properties"
$ connect-distributed connect-distributed.properties

Notice: Not using -daemon here

If you no longer have ConsoleAppender in the log4j properties, this will output next to nothing, and just hang, so would be good to nohup it.

---

The default log4j config is named connect-log4j.properties , and in Confluent Platform, this is at etc/kafka/ folder. This is what it looks like by default

log4j.rootLogger=INFO, stdout

log4j.appender.stdout=org.apache.log4j.ConsoleAppender

In order to set a max log file size, you'll need change the root logger to go to a FileAppender rather than ConsoleAppender, but I prefer using a DailyRollingFileAppender .

Here is an example

log4j.rootLogger=INFO, stdout, FILE

log4j.appender.FILE=org.apache.log4j.DailyRollingFileAppender
log4j.appender.FILE.DatePattern='.'yyyy-MM-dd
log4j.appender.FILE.File=/var/log/kafka-connect/connect.log
log4j.appender.FILE.layout=org.apache.log4j.PatternLayout
log4j.appender.FILE.layout.ConversionPattern=[%d] %p %m (%c)%n

log4j.appender.stdout=org.apache.log4j.ConsoleAppender
log4j.appender.stdout.layout=org.apache.log4j.PatternLayout
log4j.appender.stdout.layout.ConversionPattern=[%d] %p %m (%c:%L)%n

log4j.logger.org.apache.zookeeper=ERROR
log4j.logger.org.I0Itec.zkclient=ERROR
log4j.logger.org.reflections=ERROR

Answer 2

I don't have enough reputation to comment (but I can answer...) so I just want to point out in response to cricket's answer I would NOT use DailyRollingFileAppender. In the docs themselves it says it is unadvised due to synchronization and data loss issues. Instead I would use RollingFileAppender in conjunction with TimeBasedRollingPolicy. I noticed this after some odd behavior with DailyRollingFileAppender in Kafka Connect. You will need to include the log4j "extras" jar in the classpath to make this work.